You get some of the privileges of becoming an adult — some big and some small. You can vote. You can get a tattoo, buy cigarettes or go to a strip club.

At 18, you can buy a gun, which means you have responsibility to safeguard your life and the lives of others. At 18, you can enlist in the military, and put your life on the line to protect your country. At 18, you can adopt a child, taking on the responsibility of another human being.

One thing you can't do as an 18-year-old in Arizona, however, is play the lottery.

Hundreds of millions of dollars are at stake in the Mega Millions game after no one won the pool in Tuesday night's drawing — in fact, Friday's draw will be for $508 million — but no one under age 21 can play in the state of Arizona.

Of the 42 states that participate in the lottery, only four require participants to be over 18 years of age. Arizona, Iowa and Louisiana require players to be 21, and Nebraska requires them to be 19.

Arizona House Bill 2134, originally passed in 1998, listed the legal gambling age as 18. A few years later, the Legislature raised the age so that "from and after May 31, 2003, it is unlawful for a person to sell or offer to sell a lottery ticket or share to any person under the age of twenty-one years."

Minutes from the Senate meetings in 2000 about this bill explained that the Legislature wanted to make gambling less accessible to younger people. Lawmakers said they believed this problem could equal or surpass the problem of youth substance abuse.

"Cathi Herrod, legislative counsel, Center for Arizona Policy, spoke in support of the bill," according to the document. "She distributed a fact sheet on this bill, and said the fastest-growing addiction among young people today is gambling."

Herrod argued that substance abuse and criminal activity increase when teens get involved in gambling, and that the bill would help alleviate that issue.

People who recently found out about this law shared their opinions on the matter this week.

“We need one age for adulthood. ... It seems so arbitrary that one can't buy a beer, but can buy a gun, or can't buy a lottery ticket, but can serve in Baghdad.”

Jennifer Krushas

One Facebook user, Jennifer Krushas, argued for a consistent age of adulthood.

"We need one age for adulthood," said Krushas, 47. "If it's 18, that's fine. But, it needs to be consistent. You can vote, serve in the military, play the lottery, buy alcohol/pot/gun, rent a car, serve time like an adult, sign for your own medical care, etc. 18? 21? I don't really care. But, it seems so arbitrary that one can't buy a beer, but can buy a gun, or can't buy a lottery ticket, but can serve in Baghdad."

Another Facebook user, Arren Kimbel-Sannit, said he can see how this may seem like a good idea, helping to keep young adults from being economically irresponsible, but he thinks that there are people of all ages who make irresponsible decisions with their money.

"I think it should be 18," Kimbel-Sannit, 19, said. "Arizona government officials often talk a big game about their visions of libertarian freedom, yet continue to impose puritanical mindsets on private affairs, such as this one. So, for the sake of constancy within the state's frequent rhetoric, 18 is really the only number that is sensible, even within the lottery, which often makes very little sense."